Required Muscle Names and Muscle
Chapter 3 – Musculoskeletal Anatomy
and Basic Resistance Training Actions
To properly define a muscle action you must list both
the joint being moved and the type of joint motion.
- Anterior (or ventral) – front side of the body Sternocleidomastoid
Caudal – in quadrupeds, the tail end (see inferior)
Both sides working together produce flexion at
- Cranial (or superior) – above or near the head the neck (cervical flexion). The right
sternocleidomastoid produces rotation to the
- Distal – farthest end from the trunk or head
left and lateral flexion to the right. The left
- Inferior – below also, toward the feet sternocleidomastoid produces rotation to the
right and lateral flexion to the left.
Infra – prefix meaning below or under
- Lateral – away from the midline
Deltoid (anterior, medial (or lateral), and posterior
- Medial – toward the midline heads)
- Posterior (or dorsal) – back side of the body, also
Abduction of the arm (all sections). The anterior
known as the dorsal fibres flex and horizontally adduct arm and the
- Proximal – closest part nearest the trunk or head posterior fibres extend and horizontally abduct
- Superior – above or near the head, also known as the arm. This muscle should not be treated as a
single muscle due to the opposite action of the
cranial anterior and posterior fibres.
Supra – prefix meaning above or over
Extension and adduction at the shoulder joint.
Pectoralis major (clavicular head and sternal
Flexion, horizontal adduction and adduction at
the shoulder joint. When the shoulder is flexed
the pectoralis major will also act as an
extensor. Note: When designing basic
resistance training programs, there is no need
to distinguish between the clavicular and
sternal heads of this muscle.
Flexion at the elbow joint; also a weak flexor of
the shoulder. Many students think the biceps is
the primary and strongest elbow flexor. In fact,
the biceps is the strongest elbow flexor when
the forearm is supinated (palm toward the
body). However, if the forearm is pronated
(palm away from the body), the brachioradialis
is the strongest forearm flexor. Brachialis common insertion. It is a deep-lying muscle with
fibres running from the lumbar vertebrae and
Flexion of the elbow.
iliac bone to the front of the thigh (femur). As
Brachioradialis the psoas attaches to the spine it is a very
Flexion of the elbow.
important muscle in relation to back pain and I
will discuss this later in the text.
Extension at the elbow joint. Gluteus Maximus
Extension at the hip.
Trapezius (lower, middle, and upper fibres)
Quadriceps (rectus femoris, vastus intermedius,
The trapezius is very important for many
shoulder girdle movements but its action on the lateralis & medialis)
scapula is quite complex and not emphasized in Extension at the knee (all four muscles). You
this text. Some of the fibres also act on the should understand